/*
 * lcp.c - PPP Link Control Protocol.
 *
 * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The name "Carnegie Mellon University" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For permission or any legal
 *    details, please contact
 *      Office of Technology Transfer
 *      Carnegie Mellon University
 *      5000 Forbes Avenue
 *      Pittsburgh, PA  15213-3890
 *      (412) 268-4387, fax: (412) 268-7395
 *      tech-transfer@andrew.cmu.edu
 *
 * 4. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by Computing Services
 *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
 *
 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
 * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "netif/ppp/ppp_opts.h"
#if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */

/*
 * @todo:
 */

#if 0 /* UNUSED */
	#include <stdio.h>
	#include <string.h>
	#include <stdlib.h>
#endif /* UNUSED */

#include "netif/ppp/ppp_impl.h"

#include "netif/ppp/fsm.h"
#include "netif/ppp/lcp.h"
#if CHAP_SUPPORT
	#include "netif/ppp/chap-new.h"
#endif /* CHAP_SUPPORT */
#include "netif/ppp/magic.h"

/*
 * When the link comes up we want to be able to wait for a short while,
 * or until seeing some input from the peer, before starting to send
 * configure-requests.  We do this by delaying the fsm_lowerup call.
 */
/* steal a bit in fsm flags word */
#define DELAYED_UP	0x80

static void lcp_delayed_up(void* arg);

/*
 * LCP-related command-line options.
 */
#if 0 /* UNUSED */
	int	lcp_echo_interval = 0; 	/* Interval between LCP echo-requests */
	int	lcp_echo_fails = 0;	/* Tolerance to unanswered echo-requests */
#endif /* UNUSED */

#if 0 /* UNUSED */
	/* options */
	static u_int lcp_echo_interval      = LCP_ECHOINTERVAL; /* Interval between LCP echo-requests */
	static u_int lcp_echo_fails         = LCP_MAXECHOFAILS; /* Tolerance to unanswered echo-requests */
#endif /* UNUSED */

#if 0 /* UNUSED */
	#if PPP_LCP_ADAPTIVE
		bool	lcp_echo_adaptive = 0;	/* request echo only if the link was idle */
	#endif
	bool	lax_recv = 0;		/* accept control chars in asyncmap */
	bool	noendpoint = 0;		/* don't send/accept endpoint discriminator */
#endif /* UNUSED */

#if PPP_OPTIONS
	static int noopt(char**);
#endif /* PPP_OPTIONS */

#ifdef HAVE_MULTILINK
static int setendpoint(char**);
static void printendpoint(option_t*, void (*)(void*, char*, ...),
                          void*);
#endif /* HAVE_MULTILINK */

#if PPP_OPTIONS
static option_t lcp_option_list[] = {
	/* LCP options */
	{
		"-all", o_special_noarg, (void*)noopt,
		"Don't request/allow any LCP options"
	},

	{
		"noaccomp", o_bool, &lcp_wantoptions[0].neg_accompression,
		"Disable address/control compression",
		OPT_A2CLR, &lcp_allowoptions[0].neg_accompression
	},
	{
		"-ac", o_bool, &lcp_wantoptions[0].neg_accompression,
		"Disable address/control compression",
		OPT_ALIAS | OPT_A2CLR, &lcp_allowoptions[0].neg_accompression
	},

	{
		"asyncmap", o_uint32, &lcp_wantoptions[0].asyncmap,
		"Set asyncmap (for received packets)",
		OPT_OR, &lcp_wantoptions[0].neg_asyncmap
	},
	{
		"-as", o_uint32, &lcp_wantoptions[0].asyncmap,
		"Set asyncmap (for received packets)",
		OPT_ALIAS | OPT_OR, &lcp_wantoptions[0].neg_asyncmap
	},
	{
		"default-asyncmap", o_uint32, &lcp_wantoptions[0].asyncmap,
		"Disable asyncmap negotiation",
		OPT_OR | OPT_NOARG | OPT_VAL(~0U) | OPT_A2CLR,
		&lcp_allowoptions[0].neg_asyncmap
	},
	{
		"-am", o_uint32, &lcp_wantoptions[0].asyncmap,
		"Disable asyncmap negotiation",
		OPT_ALIAS | OPT_OR | OPT_NOARG | OPT_VAL(~0U) | OPT_A2CLR,
		&lcp_allowoptions[0].neg_asyncmap
	},

	{
		"nomagic", o_bool, &lcp_wantoptions[0].neg_magicnumber,
		"Disable magic number negotiation (looped-back line detection)",
		OPT_A2CLR, &lcp_allowoptions[0].neg_magicnumber
	},
	{
		"-mn", o_bool, &lcp_wantoptions[0].neg_magicnumber,
		"Disable magic number negotiation (looped-back line detection)",
		OPT_ALIAS | OPT_A2CLR, &lcp_allowoptions[0].neg_magicnumber
	},

	{
		"mru", o_int, &lcp_wantoptions[0].mru,
		"Set MRU (maximum received packet size) for negotiation",
		OPT_PRIO, &lcp_wantoptions[0].neg_mru
	},
	{
		"default-mru", o_bool, &lcp_wantoptions[0].neg_mru,
		"Disable MRU negotiation (use default 1500)",
		OPT_PRIOSUB | OPT_A2CLR, &lcp_allowoptions[0].neg_mru
	},
	{
		"-mru", o_bool, &lcp_wantoptions[0].neg_mru,
		"Disable MRU negotiation (use default 1500)",
		OPT_ALIAS | OPT_PRIOSUB | OPT_A2CLR, &lcp_allowoptions[0].neg_mru
	},

	{
		"mtu", o_int, &lcp_allowoptions[0].mru,
		"Set our MTU", OPT_LIMITS, NULL, MAXMRU, MINMRU
	},

	{
		"nopcomp", o_bool, &lcp_wantoptions[0].neg_pcompression,
		"Disable protocol field compression",
		OPT_A2CLR, &lcp_allowoptions[0].neg_pcompression
	},
	{
		"-pc", o_bool, &lcp_wantoptions[0].neg_pcompression,
		"Disable protocol field compression",
		OPT_ALIAS | OPT_A2CLR, &lcp_allowoptions[0].neg_pcompression
	},

	{
		"passive", o_bool, &lcp_wantoptions[0].passive,
		"Set passive mode", 1
	},
	{
		"-p", o_bool, &lcp_wantoptions[0].passive,
		"Set passive mode", OPT_ALIAS | 1
	},

	{
		"silent", o_bool, &lcp_wantoptions[0].silent,
		"Set silent mode", 1
	},

	{
		"lcp-echo-failure", o_int, &lcp_echo_fails,
		"Set number of consecutive echo failures to indicate link failure",
		OPT_PRIO
	},
	{
		"lcp-echo-interval", o_int, &lcp_echo_interval,
		"Set time in seconds between LCP echo requests", OPT_PRIO
	},
#if PPP_LCP_ADAPTIVE
	{
		"lcp-echo-adaptive", o_bool, &lcp_echo_adaptive,
		"Suppress LCP echo requests if traffic was received", 1
	},
#endif
	{
		"lcp-restart", o_int, &lcp_fsm[0].timeouttime,
		"Set time in seconds between LCP retransmissions", OPT_PRIO
	},
	{
		"lcp-max-terminate", o_int, &lcp_fsm[0].maxtermtransmits,
		"Set maximum number of LCP terminate-request transmissions", OPT_PRIO
	},
	{
		"lcp-max-configure", o_int, &lcp_fsm[0].maxconfreqtransmits,
		"Set maximum number of LCP configure-request transmissions", OPT_PRIO
	},
	{
		"lcp-max-failure", o_int, &lcp_fsm[0].maxnakloops,
		"Set limit on number of LCP configure-naks", OPT_PRIO
	},

	{
		"receive-all", o_bool, &lax_recv,
		"Accept all received control characters", 1
	},

#ifdef HAVE_MULTILINK
	{
		"mrru", o_int, &lcp_wantoptions[0].mrru,
		"Maximum received packet size for multilink bundle",
		OPT_PRIO, &lcp_wantoptions[0].neg_mrru
	},

	{
		"mpshortseq", o_bool, &lcp_wantoptions[0].neg_ssnhf,
		"Use short sequence numbers in multilink headers",
		OPT_PRIO | 1, &lcp_allowoptions[0].neg_ssnhf
	},
	{
		"nompshortseq", o_bool, &lcp_wantoptions[0].neg_ssnhf,
		"Don't use short sequence numbers in multilink headers",
		OPT_PRIOSUB | OPT_A2CLR, &lcp_allowoptions[0].neg_ssnhf
	},

	{
		"endpoint", o_special, (void*) setendpoint,
		"Endpoint discriminator for multilink",
		OPT_PRIO | OPT_A2PRINTER, (void*) printendpoint
	},
#endif /* HAVE_MULTILINK */

	{
		"noendpoint", o_bool, &noendpoint,
		"Don't send or accept multilink endpoint discriminator", 1
	},

	{NULL}
};
#endif /* PPP_OPTIONS */

/*
 * Callbacks for fsm code.  (CI = Configuration Information)
 */
static void lcp_resetci(fsm* f);	/* Reset our CI */
static int  lcp_cilen(fsm* f);		/* Return length of our CI */
static void lcp_addci(fsm* f, u_char* ucp, int* lenp); /* Add our CI to pkt */
static int  lcp_ackci(fsm* f, u_char* p, int len); /* Peer ack'd our CI */
static int  lcp_nakci(fsm* f, u_char* p, int len, int treat_as_reject); /* Peer nak'd our CI */
static int  lcp_rejci(fsm* f, u_char* p, int len); /* Peer rej'd our CI */
static int  lcp_reqci(fsm* f, u_char* inp, int* lenp, int reject_if_disagree); /* Rcv peer CI */
static void lcp_up(fsm* f);		/* We're UP */
static void lcp_down(fsm* f);		/* We're DOWN */
static void lcp_starting(fsm*);	/* We need lower layer up */
static void lcp_finished(fsm*);	/* We need lower layer down */
static int  lcp_extcode(fsm* f, int code, int id, u_char* inp, int len);
static void lcp_rprotrej(fsm* f, u_char* inp, int len);

/*
 * routines to send LCP echos to peer
 */

static void lcp_echo_lowerup(ppp_pcb* pcb);
static void lcp_echo_lowerdown(ppp_pcb* pcb);
static void LcpEchoTimeout(void* arg);
static void lcp_received_echo_reply(fsm* f, int id, u_char* inp, int len);
static void LcpSendEchoRequest(fsm* f);
static void LcpLinkFailure(fsm* f);
static void LcpEchoCheck(fsm* f);

static const fsm_callbacks lcp_callbacks = {	/* LCP callback routines */
	lcp_resetci,		/* Reset our Configuration Information */
	lcp_cilen,			/* Length of our Configuration Information */
	lcp_addci,			/* Add our Configuration Information */
	lcp_ackci,			/* ACK our Configuration Information */
	lcp_nakci,			/* NAK our Configuration Information */
	lcp_rejci,			/* Reject our Configuration Information */
	lcp_reqci,			/* Request peer's Configuration Information */
	lcp_up,			/* Called when fsm reaches OPENED state */
	lcp_down,			/* Called when fsm leaves OPENED state */
	lcp_starting,		/* Called when we want the lower layer up */
	lcp_finished,		/* Called when we want the lower layer down */
	NULL,			/* Called when Protocol-Reject received */
	NULL,			/* Retransmission is necessary */
	lcp_extcode,		/* Called to handle LCP-specific codes */
	"LCP"			/* String name of protocol */
};

/*
 * Protocol entry points.
 * Some of these are called directly.
 */

static void lcp_init(ppp_pcb* pcb);
static void lcp_input(ppp_pcb* pcb, u_char* p, int len);
static void lcp_protrej(ppp_pcb* pcb);
#if PRINTPKT_SUPPORT
static int lcp_printpkt(const u_char* p, int plen,
                        void (*printer)(void*, const char*, ...), void* arg);
#endif /* PRINTPKT_SUPPORT */

const struct protent lcp_protent = {
	PPP_LCP,
	lcp_init,
	lcp_input,
	lcp_protrej,
	lcp_lowerup,
	lcp_lowerdown,
	lcp_open,
	lcp_close,
#if PRINTPKT_SUPPORT
	lcp_printpkt,
#endif /* PRINTPKT_SUPPORT */
#if PPP_DATAINPUT
	NULL,
#endif /* PPP_DATAINPUT */
#if PRINTPKT_SUPPORT
	"LCP",
	NULL,
#endif /* PRINTPKT_SUPPORT */
#if PPP_OPTIONS
	lcp_option_list,
	NULL,
#endif /* PPP_OPTIONS */
#if DEMAND_SUPPORT
	NULL,
	NULL
#endif /* DEMAND_SUPPORT */
};

/*
 * Length of each type of configuration option (in octets)
 */
#define CILEN_VOID	2
#define CILEN_CHAR	3
#define CILEN_SHORT	4	/* CILEN_VOID + 2 */
#if CHAP_SUPPORT
	#define CILEN_CHAP	5	/* CILEN_VOID + 2 + 1 */
#endif /* CHAP_SUPPORT */
#define CILEN_LONG	6	/* CILEN_VOID + 4 */
#if LQR_SUPPORT
	#define CILEN_LQR	8	/* CILEN_VOID + 2 + 4 */
#endif /* LQR_SUPPORT */
#define CILEN_CBCP	3

#define CODENAME(x)	((x) == CONFACK ? "ACK" : \
			 (x) == CONFNAK ? "NAK" : "REJ")

#if PPP_OPTIONS
/*
 * noopt - Disable all options (why?).
 */
static int
noopt(argv)
char** argv;
{
	BZERO((char*) &lcp_wantoptions[0], sizeof(struct lcp_options));
	BZERO((char*) &lcp_allowoptions[0], sizeof(struct lcp_options));

	return (1);
}
#endif /* PPP_OPTIONS */

#ifdef HAVE_MULTILINK
static int
setendpoint(argv)
char** argv;
{
	if(str_to_epdisc(&lcp_wantoptions[0].endpoint, *argv)) {
		lcp_wantoptions[0].neg_endpoint = 1;
		return 1;
	}

	option_error("Can't parse '%s' as an endpoint discriminator", *argv);
	return 0;
}

static void
printendpoint(opt, printer, arg)
option_t* opt;
void (*printer)(void*, char*, ...);
void* arg;
{
	printer(arg, "%s", epdisc_to_str(&lcp_wantoptions[0].endpoint));
}
#endif /* HAVE_MULTILINK */

/*
 * lcp_init - Initialize LCP.
 */
static void lcp_init(ppp_pcb* pcb)
{
	fsm* f = &pcb->lcp_fsm;
	lcp_options* wo = &pcb->lcp_wantoptions;
	lcp_options* ao = &pcb->lcp_allowoptions;

	f->pcb = pcb;
	f->protocol = PPP_LCP;
	f->callbacks = &lcp_callbacks;

	fsm_init(f);

	BZERO(wo, sizeof(*wo));
	wo->neg_mru = 1;
	wo->mru = PPP_DEFMRU;
	wo->neg_asyncmap = 1;
	wo->neg_magicnumber = 1;
	wo->neg_pcompression = 1;
	wo->neg_accompression = 1;

	BZERO(ao, sizeof(*ao));
	ao->neg_mru = 1;
	ao->mru = PPP_MAXMRU;
	ao->neg_asyncmap = 1;
#if CHAP_SUPPORT
	ao->neg_chap = 1;
	ao->chap_mdtype = CHAP_MDTYPE_SUPPORTED;
#endif /* CHAP_SUPPORT */
#if PAP_SUPPORT
	ao->neg_upap = 1;
#endif /* PAP_SUPPORT */
#if EAP_SUPPORT
	ao->neg_eap = 1;
#endif /* EAP_SUPPORT */
	ao->neg_magicnumber = 1;
	ao->neg_pcompression = 1;
	ao->neg_accompression = 1;
	ao->neg_endpoint = 1;
}


/*
 * lcp_open - LCP is allowed to come up.
 */
void lcp_open(ppp_pcb* pcb)
{
	fsm* f = &pcb->lcp_fsm;
	lcp_options* wo = &pcb->lcp_wantoptions;

	f->flags &= ~(OPT_PASSIVE | OPT_SILENT);

	if(wo->passive)
		f->flags |= OPT_PASSIVE;

	if(wo->silent)
		f->flags |= OPT_SILENT;

	fsm_open(f);
}


/*
 * lcp_close - Take LCP down.
 */
void lcp_close(ppp_pcb* pcb, const char* reason)
{
	fsm* f = &pcb->lcp_fsm;
	int oldstate;

	if(pcb->phase != PPP_PHASE_DEAD
#ifdef HAVE_MULTILINK
	        && pcb->phase != PPP_PHASE_MASTER
#endif /* HAVE_MULTILINK */
	  )
		new_phase(pcb, PPP_PHASE_TERMINATE);

	if(f->flags & DELAYED_UP) {
		UNTIMEOUT(lcp_delayed_up, f);
		f->state = PPP_FSM_STOPPED;
	}

	oldstate = f->state;

	fsm_close(f, reason);

	if(oldstate == PPP_FSM_STOPPED && (f->flags & (OPT_PASSIVE | OPT_SILENT | DELAYED_UP))) {
		/*
		 * This action is not strictly according to the FSM in RFC1548,
		 * but it does mean that the program terminates if you do a
		 * lcp_close() when a connection hasn't been established
		 * because we are in passive/silent mode or because we have
		 * delayed the fsm_lowerup() call and it hasn't happened yet.
		 */
		f->flags &= ~DELAYED_UP;
		lcp_finished(f);
	}
}


/*
 * lcp_lowerup - The lower layer is up.
 */
void lcp_lowerup(ppp_pcb* pcb)
{
	lcp_options* wo = &pcb->lcp_wantoptions;
	fsm* f = &pcb->lcp_fsm;

	/*
	 * Don't use A/C or protocol compression on transmission,
	 * but accept A/C and protocol compressed packets
	 * if we are going to ask for A/C and protocol compression.
	 */
	if(ppp_send_config(pcb, PPP_MRU, 0xffffffff, 0, 0) < 0
	        || ppp_recv_config(pcb, PPP_MRU, (pcb->settings.lax_recv ? 0 : 0xffffffff),
	                           wo->neg_pcompression, wo->neg_accompression) < 0)
		return;

	pcb->peer_mru = PPP_MRU;

	if(pcb->settings.listen_time != 0) {
		f->flags |= DELAYED_UP;
		TIMEOUTMS(lcp_delayed_up, f, pcb->settings.listen_time);
	} else
		fsm_lowerup(f);
}


/*
 * lcp_lowerdown - The lower layer is down.
 */
void lcp_lowerdown(ppp_pcb* pcb)
{
	fsm* f = &pcb->lcp_fsm;

	if(f->flags & DELAYED_UP) {
		f->flags &= ~DELAYED_UP;
		UNTIMEOUT(lcp_delayed_up, f);
	} else
		fsm_lowerdown(f);
}


/*
 * lcp_delayed_up - Bring the lower layer up now.
 */
static void lcp_delayed_up(void* arg)
{
	fsm* f = (fsm*)arg;

	if(f->flags & DELAYED_UP) {
		f->flags &= ~DELAYED_UP;
		fsm_lowerup(f);
	}
}


/*
 * lcp_input - Input LCP packet.
 */
static void lcp_input(ppp_pcb* pcb, u_char* p, int len)
{
	fsm* f = &pcb->lcp_fsm;

	if(f->flags & DELAYED_UP) {
		f->flags &= ~DELAYED_UP;
		UNTIMEOUT(lcp_delayed_up, f);
		fsm_lowerup(f);
	}

	fsm_input(f, p, len);
}

/*
 * lcp_extcode - Handle a LCP-specific code.
 */
static int lcp_extcode(fsm* f, int code, int id, u_char* inp, int len)
{
	ppp_pcb* pcb = f->pcb;
	lcp_options* go = &pcb->lcp_gotoptions;
	u_char* magp;

	switch(code) {
		case PROTREJ:
			lcp_rprotrej(f, inp, len);
			break;

		case ECHOREQ:
			if(f->state != PPP_FSM_OPENED)
				break;

			magp = inp;
			PUTLONG(go->magicnumber, magp);
			fsm_sdata(f, ECHOREP, id, inp, len);
			break;

		case ECHOREP:
			lcp_received_echo_reply(f, id, inp, len);
			break;

		case DISCREQ:
		case IDENTIF:
		case TIMEREM:
			break;

		default:
			return 0;
	}

	return 1;
}


/*
 * lcp_rprotrej - Receive an Protocol-Reject.
 *
 * Figure out which protocol is rejected and inform it.
 */
static void lcp_rprotrej(fsm* f, u_char* inp, int len)
{
	int i;
	const struct protent* protp;
	u_short prot;
#if PPP_PROTOCOLNAME
	const char* pname;
#endif /* PPP_PROTOCOLNAME */

	if(len < 2) {
		LCPDEBUG(("lcp_rprotrej: Rcvd short Protocol-Reject packet!"));
		return;
	}

	GETSHORT(prot, inp);

	/*
	 * Protocol-Reject packets received in any state other than the LCP
	 * OPENED state SHOULD be silently discarded.
	 */
	if(f->state != PPP_FSM_OPENED) {
		LCPDEBUG(("Protocol-Reject discarded: LCP in state %d", f->state));
		return;
	}

#if PPP_PROTOCOLNAME
	pname = protocol_name(prot);
#endif /* PPP_PROTOCOLNAME */

	/*
	 * Upcall the proper Protocol-Reject routine.
	 */
	for(i = 0; (protp = protocols[i]) != NULL; ++i)
		if(protp->protocol == prot) {
#if PPP_PROTOCOLNAME

			if(pname != NULL)
				ppp_dbglog("Protocol-Reject for '%s' (0x%x) received", pname,
				           prot);
			else
#endif /* PPP_PROTOCOLNAME */
				ppp_dbglog("Protocol-Reject for 0x%x received", prot);

			(*protp->protrej)(f->pcb);
			return;
		}

#if PPP_PROTOCOLNAME

	if(pname != NULL)
		ppp_warn("Protocol-Reject for unsupported protocol '%s' (0x%x)", pname,
		         prot);
	else
#endif /* #if PPP_PROTOCOLNAME */
		ppp_warn("Protocol-Reject for unsupported protocol 0x%x", prot);
}


/*
 * lcp_protrej - A Protocol-Reject was received.
 */
/*ARGSUSED*/
static void lcp_protrej(ppp_pcb* pcb)
{
	/*
	 * Can't reject LCP!
	 */
	ppp_error("Received Protocol-Reject for LCP!");
	fsm_protreject(&pcb->lcp_fsm);
}


/*
 * lcp_sprotrej - Send a Protocol-Reject for some protocol.
 */
void lcp_sprotrej(ppp_pcb* pcb, u_char* p, int len)
{
	fsm* f = &pcb->lcp_fsm;
	/*
	 * Send back the protocol and the information field of the
	 * rejected packet.  We only get here if LCP is in the OPENED state.
	 */
#if 0
	p += 2;
	len -= 2;
#endif

	fsm_sdata(f, PROTREJ, ++f->id,
	          p, len);
}


/*
 * lcp_resetci - Reset our CI.
 */
static void lcp_resetci(fsm* f)
{
	ppp_pcb* pcb = f->pcb;
	lcp_options* wo = &pcb->lcp_wantoptions;
	lcp_options* go = &pcb->lcp_gotoptions;
	lcp_options* ao = &pcb->lcp_allowoptions;

#if PPP_AUTH_SUPPORT

	/* note: default value is true for allow options */
	if(pcb->settings.user && pcb->settings.passwd) {
#if PAP_SUPPORT

		if(pcb->settings.refuse_pap) {
			ao->neg_upap = 0;
		}

#endif /* PAP_SUPPORT */
#if CHAP_SUPPORT

		if(pcb->settings.refuse_chap) {
			ao->chap_mdtype &= ~MDTYPE_MD5;
		}

#if MSCHAP_SUPPORT

		if(pcb->settings.refuse_mschap) {
			ao->chap_mdtype &= ~MDTYPE_MICROSOFT;
		}

		if(pcb->settings.refuse_mschap_v2) {
			ao->chap_mdtype &= ~MDTYPE_MICROSOFT_V2;
		}

#endif /* MSCHAP_SUPPORT */
		ao->neg_chap = (ao->chap_mdtype != MDTYPE_NONE);
#endif /* CHAP_SUPPORT */
#if EAP_SUPPORT

		if(pcb->settings.refuse_eap) {
			ao->neg_eap = 0;
		}

#endif /* EAP_SUPPORT */

#if PPP_SERVER

		/* note: default value is false for wanted options */
		if(pcb->settings.auth_required) {
#if PAP_SUPPORT

			if(!pcb->settings.refuse_pap) {
				wo->neg_upap = 1;
			}

#endif /* PAP_SUPPORT */
#if CHAP_SUPPORT

			if(!pcb->settings.refuse_chap) {
				wo->chap_mdtype |= MDTYPE_MD5;
			}

#if MSCHAP_SUPPORT

			if(!pcb->settings.refuse_mschap) {
				wo->chap_mdtype |= MDTYPE_MICROSOFT;
			}

			if(!pcb->settings.refuse_mschap_v2) {
				wo->chap_mdtype |= MDTYPE_MICROSOFT_V2;
			}

#endif /* MSCHAP_SUPPORT */
			wo->neg_chap = (wo->chap_mdtype != MDTYPE_NONE);
#endif /* CHAP_SUPPORT */
#if EAP_SUPPORT

			if(!pcb->settings.refuse_eap) {
				wo->neg_eap = 1;
			}

#endif /* EAP_SUPPORT */
		}

#endif /* PPP_SERVER */

	} else {
#if PAP_SUPPORT
		ao->neg_upap = 0;
#endif /* PAP_SUPPORT */
#if CHAP_SUPPORT
		ao->neg_chap = 0;
		ao->chap_mdtype = MDTYPE_NONE;
#endif /* CHAP_SUPPORT */
#if EAP_SUPPORT
		ao->neg_eap = 0;
#endif /* EAP_SUPPORT */
	}

	PPPDEBUG(LOG_DEBUG, ("ppp: auth protocols:"));
#if PAP_SUPPORT
	PPPDEBUG(LOG_DEBUG, (" PAP=%d", ao->neg_upap));
#endif /* PAP_SUPPORT */
#if CHAP_SUPPORT
	PPPDEBUG(LOG_DEBUG, (" CHAP=%d CHAP_MD5=%d", ao->neg_chap, !!(ao->chap_mdtype & MDTYPE_MD5)));
#if MSCHAP_SUPPORT
	PPPDEBUG(LOG_DEBUG, (" CHAP_MS=%d CHAP_MS2=%d", !!(ao->chap_mdtype & MDTYPE_MICROSOFT), !!(ao->chap_mdtype & MDTYPE_MICROSOFT_V2)));
#endif /* MSCHAP_SUPPORT */
#endif /* CHAP_SUPPORT */
#if EAP_SUPPORT
	PPPDEBUG(LOG_DEBUG, (" EAP=%d", ao->neg_eap));
#endif /* EAP_SUPPORT */
	PPPDEBUG(LOG_DEBUG, ("\n"));

#endif /* PPP_AUTH_SUPPORT */

	wo->magicnumber = magic();
	wo->numloops = 0;
	*go = *wo;
#ifdef HAVE_MULTILINK

	if(!multilink) {
		go->neg_mrru = 0;
#endif /* HAVE_MULTILINK */
		go->neg_ssnhf = 0;
		go->neg_endpoint = 0;
#ifdef HAVE_MULTILINK
	}

#endif /* HAVE_MULTILINK */

	if(pcb->settings.noendpoint)
		ao->neg_endpoint = 0;

	pcb->peer_mru = PPP_MRU;
#if 0 /* UNUSED */
	auth_reset(pcb);
#endif /* UNUSED */
}


/*
 * lcp_cilen - Return length of our CI.
 */
static int lcp_cilen(fsm* f)
{
	ppp_pcb* pcb = f->pcb;
	lcp_options* go = &pcb->lcp_gotoptions;

#define LENCIVOID(neg)	((neg) ? CILEN_VOID : 0)
#if CHAP_SUPPORT
#define LENCICHAP(neg)	((neg) ? CILEN_CHAP : 0)
#endif /* CHAP_SUPPORT */
#define LENCISHORT(neg)	((neg) ? CILEN_SHORT : 0)
#define LENCILONG(neg)	((neg) ? CILEN_LONG : 0)
#if LQR_SUPPORT
#define LENCILQR(neg)	((neg) ? CILEN_LQR: 0)
#endif /* LQR_SUPPORT */
#define LENCICBCP(neg)	((neg) ? CILEN_CBCP: 0)
	/*
	 * NB: we only ask for one of CHAP, UPAP, or EAP, even if we will
	 * accept more than one.  We prefer EAP first, then CHAP, then
	 * PAP.
	 */
	return (LENCISHORT(go->neg_mru && go->mru != PPP_DEFMRU) +
	        LENCILONG(go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF) +
#if EAP_SUPPORT
	        LENCISHORT(go->neg_eap) +
#endif /* EAP_SUPPORT */
#if CHAP_SUPPORT /* cannot be improved, embedding a directive within macro arguments is not portable */
#if EAP_SUPPORT
	        LENCICHAP(!go->neg_eap && go->neg_chap) +
#endif /* EAP_SUPPORT */
#if !EAP_SUPPORT
	        LENCICHAP(go->neg_chap) +
#endif /* !EAP_SUPPORT */
#endif /* CHAP_SUPPORT */
#if PAP_SUPPORT /* cannot be improved, embedding a directive within macro arguments is not portable */
#if EAP_SUPPORT && CHAP_SUPPORT
	        LENCISHORT(!go->neg_eap && !go->neg_chap && go->neg_upap) +
#endif /* EAP_SUPPORT && CHAP_SUPPORT */
#if EAP_SUPPORT && !CHAP_SUPPORT
	        LENCISHORT(!go->neg_eap && go->neg_upap) +
#endif /* EAP_SUPPORT && !CHAP_SUPPORT */
#if !EAP_SUPPORT && CHAP_SUPPORT
	        LENCISHORT(!go->neg_chap && go->neg_upap) +
#endif /* !EAP_SUPPORT && CHAP_SUPPORT */
#if !EAP_SUPPORT && !CHAP_SUPPORT
	        LENCISHORT(go->neg_upap) +
#endif /* !EAP_SUPPORT && !CHAP_SUPPORT */
#endif /* PAP_SUPPORT */
#if LQR_SUPPORT
	        LENCILQR(go->neg_lqr) +
#endif /* LQR_SUPPORT */
	        LENCICBCP(go->neg_cbcp) +
	        LENCILONG(go->neg_magicnumber) +
	        LENCIVOID(go->neg_pcompression) +
	        LENCIVOID(go->neg_accompression) +
#ifdef HAVE_MULTILINK
	        LENCISHORT(go->neg_mrru) +
#endif /* HAVE_MULTILINK */
	        LENCIVOID(go->neg_ssnhf) +
	        (go->neg_endpoint ? CILEN_CHAR + go->endpoint.length : 0));
}


/*
 * lcp_addci - Add our desired CIs to a packet.
 */
static void lcp_addci(fsm* f, u_char* ucp, int* lenp)
{
	ppp_pcb* pcb = f->pcb;
	lcp_options* go = &pcb->lcp_gotoptions;
	u_char* start_ucp = ucp;

#define ADDCIVOID(opt, neg) \
    if (neg) { \
	PUTCHAR(opt, ucp); \
	PUTCHAR(CILEN_VOID, ucp); \
    }
#define ADDCISHORT(opt, neg, val) \
    if (neg) { \
	PUTCHAR(opt, ucp); \
	PUTCHAR(CILEN_SHORT, ucp); \
	PUTSHORT(val, ucp); \
    }
#if CHAP_SUPPORT
#define ADDCICHAP(opt, neg, val) \
    if (neg) { \
	PUTCHAR((opt), ucp); \
	PUTCHAR(CILEN_CHAP, ucp); \
	PUTSHORT(PPP_CHAP, ucp); \
	PUTCHAR((CHAP_DIGEST(val)), ucp); \
    }
#endif /* CHAP_SUPPORT */
#define ADDCILONG(opt, neg, val) \
    if (neg) { \
	PUTCHAR(opt, ucp); \
	PUTCHAR(CILEN_LONG, ucp); \
	PUTLONG(val, ucp); \
    }
#if LQR_SUPPORT
#define ADDCILQR(opt, neg, val) \
    if (neg) { \
	PUTCHAR(opt, ucp); \
	PUTCHAR(CILEN_LQR, ucp); \
	PUTSHORT(PPP_LQR, ucp); \
	PUTLONG(val, ucp); \
    }
#endif /* LQR_SUPPORT */
#define ADDCICHAR(opt, neg, val) \
    if (neg) { \
	PUTCHAR(opt, ucp); \
	PUTCHAR(CILEN_CHAR, ucp); \
	PUTCHAR(val, ucp); \
    }
#define ADDCIENDP(opt, neg, class, val, len) \
    if (neg) { \
	int i; \
	PUTCHAR(opt, ucp); \
	PUTCHAR(CILEN_CHAR + len, ucp); \
	PUTCHAR(class, ucp); \
	for (i = 0; i < len; ++i) \
	    PUTCHAR(val[i], ucp); \
    }

	ADDCISHORT(CI_MRU, go->neg_mru && go->mru != PPP_DEFMRU, go->mru);
	ADDCILONG(CI_ASYNCMAP, go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF,
	          go->asyncmap);
#if EAP_SUPPORT
	ADDCISHORT(CI_AUTHTYPE, go->neg_eap, PPP_EAP);
#endif /* EAP_SUPPORT */
#if CHAP_SUPPORT /* cannot be improved, embedding a directive within macro arguments is not portable */
#if EAP_SUPPORT
	ADDCICHAP(CI_AUTHTYPE, !go->neg_eap && go->neg_chap, go->chap_mdtype);
#endif /* EAP_SUPPORT */
#if !EAP_SUPPORT
	ADDCICHAP(CI_AUTHTYPE, go->neg_chap, go->chap_mdtype);
#endif /* !EAP_SUPPORT */
#endif /* CHAP_SUPPORT */
#if PAP_SUPPORT /* cannot be improved, embedding a directive within macro arguments is not portable */
#if EAP_SUPPORT && CHAP_SUPPORT
	ADDCISHORT(CI_AUTHTYPE, !go->neg_eap && !go->neg_chap && go->neg_upap, PPP_PAP);
#endif /* EAP_SUPPORT && CHAP_SUPPORT */
#if EAP_SUPPORT && !CHAP_SUPPORT
	ADDCISHORT(CI_AUTHTYPE, !go->neg_eap && go->neg_upap, PPP_PAP);
#endif /* EAP_SUPPORT && !CHAP_SUPPORT */
#if !EAP_SUPPORT && CHAP_SUPPORT
	ADDCISHORT(CI_AUTHTYPE, !go->neg_chap && go->neg_upap, PPP_PAP);
#endif /* !EAP_SUPPORT && CHAP_SUPPORT */
#if !EAP_SUPPORT && !CHAP_SUPPORT
	ADDCISHORT(CI_AUTHTYPE, go->neg_upap, PPP_PAP);
#endif /* !EAP_SUPPORT && !CHAP_SUPPORT */
#endif /* PAP_SUPPORT */
#if LQR_SUPPORT
	ADDCILQR(CI_QUALITY, go->neg_lqr, go->lqr_period);
#endif /* LQR_SUPPORT */
	ADDCICHAR(CI_CALLBACK, go->neg_cbcp, CBCP_OPT);
	ADDCILONG(CI_MAGICNUMBER, go->neg_magicnumber, go->magicnumber);
	ADDCIVOID(CI_PCOMPRESSION, go->neg_pcompression);
	ADDCIVOID(CI_ACCOMPRESSION, go->neg_accompression);
#ifdef HAVE_MULTILINK
	ADDCISHORT(CI_MRRU, go->neg_mrru, go->mrru);
#endif
	ADDCIVOID(CI_SSNHF, go->neg_ssnhf);
	ADDCIENDP(CI_EPDISC, go->neg_endpoint, go->endpoint.class_,
	          go->endpoint.value, go->endpoint.length);

	if(ucp - start_ucp != *lenp) {
		/* this should never happen, because peer_mtu should be 1500 */
		ppp_error("Bug in lcp_addci: wrong length");
	}
}


/*
 * lcp_ackci - Ack our CIs.
 * This should not modify any state if the Ack is bad.
 *
 * Returns:
 *	0 - Ack was bad.
 *	1 - Ack was good.
 */
static int lcp_ackci(fsm* f, u_char* p, int len)
{
	ppp_pcb* pcb = f->pcb;
	lcp_options* go = &pcb->lcp_gotoptions;
	u_char cilen, citype, cichar;
	u_short cishort;
	u32_t cilong;

	/*
	 * CIs must be in exactly the same order that we sent.
	 * Check packet length and CI length at each step.
	 * If we find any deviations, then this packet is bad.
	 */
#define ACKCIVOID(opt, neg) \
    if (neg) { \
	if ((len -= CILEN_VOID) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_VOID || \
	    citype != opt) \
	    goto bad; \
    }
#define ACKCISHORT(opt, neg, val) \
    if (neg) { \
	if ((len -= CILEN_SHORT) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_SHORT || \
	    citype != opt) \
	    goto bad; \
	GETSHORT(cishort, p); \
	if (cishort != val) \
	    goto bad; \
    }
#define ACKCICHAR(opt, neg, val) \
    if (neg) { \
	if ((len -= CILEN_CHAR) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_CHAR || \
	    citype != opt) \
	    goto bad; \
	GETCHAR(cichar, p); \
	if (cichar != val) \
	    goto bad; \
    }
#if CHAP_SUPPORT
#define ACKCICHAP(opt, neg, val) \
    if (neg) { \
	if ((len -= CILEN_CHAP) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_CHAP || \
	    citype != (opt)) \
	    goto bad; \
	GETSHORT(cishort, p); \
	if (cishort != PPP_CHAP) \
	    goto bad; \
	GETCHAR(cichar, p); \
	if (cichar != (CHAP_DIGEST(val))) \
	  goto bad; \
    }
#endif /* CHAP_SUPPORT */
#define ACKCILONG(opt, neg, val) \
    if (neg) { \
	if ((len -= CILEN_LONG) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_LONG || \
	    citype != opt) \
	    goto bad; \
	GETLONG(cilong, p); \
	if (cilong != val) \
	    goto bad; \
    }
#if LQR_SUPPORT
#define ACKCILQR(opt, neg, val) \
    if (neg) { \
	if ((len -= CILEN_LQR) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_LQR || \
	    citype != opt) \
	    goto bad; \
	GETSHORT(cishort, p); \
	if (cishort != PPP_LQR) \
	    goto bad; \
	GETLONG(cilong, p); \
	if (cilong != val) \
	  goto bad; \
    }
#endif /* LQR_SUPPORT */
#define ACKCIENDP(opt, neg, class, val, vlen) \
    if (neg) { \
	int i; \
	if ((len -= CILEN_CHAR + vlen) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_CHAR + vlen || \
	    citype != opt) \
	    goto bad; \
	GETCHAR(cichar, p); \
	if (cichar != class) \
	    goto bad; \
	for (i = 0; i < vlen; ++i) { \
	    GETCHAR(cichar, p); \
	    if (cichar != val[i]) \
		goto bad; \
	} \
    }

	ACKCISHORT(CI_MRU, go->neg_mru && go->mru != PPP_DEFMRU, go->mru);
	ACKCILONG(CI_ASYNCMAP, go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF,
	          go->asyncmap);
#if EAP_SUPPORT
	ACKCISHORT(CI_AUTHTYPE, go->neg_eap, PPP_EAP);
#endif /* EAP_SUPPORT */
#if CHAP_SUPPORT /* cannot be improved, embedding a directive within macro arguments is not portable */
#if EAP_SUPPORT
	ACKCICHAP(CI_AUTHTYPE, !go->neg_eap && go->neg_chap, go->chap_mdtype);
#endif /* EAP_SUPPORT */
#if !EAP_SUPPORT
	ACKCICHAP(CI_AUTHTYPE, go->neg_chap, go->chap_mdtype);
#endif /* !EAP_SUPPORT */
#endif /* CHAP_SUPPORT */
#if PAP_SUPPORT /* cannot be improved, embedding a directive within macro arguments is not portable */
#if EAP_SUPPORT && CHAP_SUPPORT
	ACKCISHORT(CI_AUTHTYPE, !go->neg_eap && !go->neg_chap && go->neg_upap, PPP_PAP);
#endif /* EAP_SUPPORT && CHAP_SUPPORT */
#if EAP_SUPPORT && !CHAP_SUPPORT
	ACKCISHORT(CI_AUTHTYPE, !go->neg_eap && go->neg_upap, PPP_PAP);
#endif /* EAP_SUPPORT && !CHAP_SUPPORT */
#if !EAP_SUPPORT && CHAP_SUPPORT
	ACKCISHORT(CI_AUTHTYPE, !go->neg_chap && go->neg_upap, PPP_PAP);
#endif /* !EAP_SUPPORT && CHAP_SUPPORT */
#if !EAP_SUPPORT && !CHAP_SUPPORT
	ACKCISHORT(CI_AUTHTYPE, go->neg_upap, PPP_PAP);
#endif /* !EAP_SUPPORT && !CHAP_SUPPORT */
#endif /* PAP_SUPPORT */
#if LQR_SUPPORT
	ACKCILQR(CI_QUALITY, go->neg_lqr, go->lqr_period);
#endif /* LQR_SUPPORT */
	ACKCICHAR(CI_CALLBACK, go->neg_cbcp, CBCP_OPT);
	ACKCILONG(CI_MAGICNUMBER, go->neg_magicnumber, go->magicnumber);
	ACKCIVOID(CI_PCOMPRESSION, go->neg_pcompression);
	ACKCIVOID(CI_ACCOMPRESSION, go->neg_accompression);
#ifdef HAVE_MULTILINK
	ACKCISHORT(CI_MRRU, go->neg_mrru, go->mrru);
#endif /* HAVE_MULTILINK */
	ACKCIVOID(CI_SSNHF, go->neg_ssnhf);
	ACKCIENDP(CI_EPDISC, go->neg_endpoint, go->endpoint.class_,
	          go->endpoint.value, go->endpoint.length);

	/*
	 * If there are any remaining CIs, then this packet is bad.
	 */
	if(len != 0)
		goto bad;

	return (1);
bad:
	LCPDEBUG(("lcp_acki: received bad Ack!"));
	return (0);
}


/*
 * lcp_nakci - Peer has sent a NAK for some of our CIs.
 * This should not modify any state if the Nak is bad
 * or if LCP is in the OPENED state.
 *
 * Returns:
 *	0 - Nak was bad.
 *	1 - Nak was good.
 */
static int lcp_nakci(fsm* f, u_char* p, int len, int treat_as_reject)
{
	ppp_pcb* pcb = f->pcb;
	lcp_options* go = &pcb->lcp_gotoptions;
	lcp_options* wo = &pcb->lcp_wantoptions;
	u_char citype, cichar, *next;
	u_short cishort;
	u32_t cilong;
	lcp_options no;		/* options we've seen Naks for */
	lcp_options try_;		/* options to request next time */
	int looped_back = 0;
	int cilen;

	BZERO(&no, sizeof(no));
	try_ = *go;

	/*
	 * Any Nak'd CIs must be in exactly the same order that we sent.
	 * Check packet length and CI length at each step.
	 * If we find any deviations, then this packet is bad.
	 */
#define NAKCIVOID(opt, neg) \
    if (go->neg && \
	len >= CILEN_VOID && \
	p[1] == CILEN_VOID && \
	p[0] == opt) { \
	len -= CILEN_VOID; \
	INCPTR(CILEN_VOID, p); \
	no.neg = 1; \
	try_.neg = 0; \
    }
#if CHAP_SUPPORT
#define NAKCICHAP(opt, neg, code) \
    if (go->neg && \
	len >= CILEN_CHAP && \
	p[1] == CILEN_CHAP && \
	p[0] == opt) { \
	len -= CILEN_CHAP; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	GETCHAR(cichar, p); \
	no.neg = 1; \
	code \
    }
#endif /* CHAP_SUPPORT */
#define NAKCICHAR(opt, neg, code) \
    if (go->neg && \
	len >= CILEN_CHAR && \
	p[1] == CILEN_CHAR && \
	p[0] == opt) { \
	len -= CILEN_CHAR; \
	INCPTR(2, p); \
	GETCHAR(cichar, p); \
	no.neg = 1; \
	code \
    }
#define NAKCISHORT(opt, neg, code) \
    if (go->neg && \
	len >= CILEN_SHORT && \
	p[1] == CILEN_SHORT && \
	p[0] == opt) { \
	len -= CILEN_SHORT; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	no.neg = 1; \
	code \
    }
#define NAKCILONG(opt, neg, code) \
    if (go->neg && \
	len >= CILEN_LONG && \
	p[1] == CILEN_LONG && \
	p[0] == opt) { \
	len -= CILEN_LONG; \
	INCPTR(2, p); \
	GETLONG(cilong, p); \
	no.neg = 1; \
	code \
    }
#if LQR_SUPPORT
#define NAKCILQR(opt, neg, code) \
    if (go->neg && \
	len >= CILEN_LQR && \
	p[1] == CILEN_LQR && \
	p[0] == opt) { \
	len -= CILEN_LQR; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	GETLONG(cilong, p); \
	no.neg = 1; \
	code \
    }
#endif /* LQR_SUPPORT */
#define NAKCIENDP(opt, neg) \
    if (go->neg && \
	len >= CILEN_CHAR && \
	p[0] == opt && \
	p[1] >= CILEN_CHAR && \
	p[1] <= len) { \
	len -= p[1]; \
	INCPTR(p[1], p); \
	no.neg = 1; \
	try_.neg = 0; \
    }

	/*
	 * NOTE!  There must be no assignments to individual fields of *go in
	 * the code below.  Any such assignment is a BUG!
	 */
	/*
	 * We don't care if they want to send us smaller packets than
	 * we want.  Therefore, accept any MRU less than what we asked for,
	 * but then ignore the new value when setting the MRU in the kernel.
	 * If they send us a bigger MRU than what we asked, accept it, up to
	 * the limit of the default MRU we'd get if we didn't negotiate.
	 */
	if(go->neg_mru && go->mru != PPP_DEFMRU) {
		NAKCISHORT(CI_MRU, neg_mru,

		           if(cishort <= wo->mru || cishort <= PPP_DEFMRU)
		           try_.mru = cishort;
		          );
	}

	/*
	 * Add any characters they want to our (receive-side) asyncmap.
	 */
	if(go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF) {
		NAKCILONG(CI_ASYNCMAP, neg_asyncmap,
		          try_.asyncmap = go->asyncmap | cilong;
		         );
	}

	/*
	 * If they've nak'd our authentication-protocol, check whether
	 * they are proposing a different protocol, or a different
	 * hash algorithm for CHAP.
	 */
	if((0
#if CHAP_SUPPORT
	        || go->neg_chap
#endif /* CHAP_SUPPORT */
#if PAP_SUPPORT
	        || go->neg_upap
#endif /* PAP_SUPPORT */
#if EAP_SUPPORT
	        || go->neg_eap
#endif /* EAP_SUPPORT */
	   )
	        && len >= CILEN_SHORT
	        && p[0] == CI_AUTHTYPE && p[1] >= CILEN_SHORT && p[1] <= len) {
		cilen = p[1];
		len -= cilen;
#if CHAP_SUPPORT
		no.neg_chap = go->neg_chap;
#endif /* CHAP_SUPPORT */
#if PAP_SUPPORT
		no.neg_upap = go->neg_upap;
#endif /* PAP_SUPPORT */
#if EAP_SUPPORT
		no.neg_eap = go->neg_eap;
#endif /* EAP_SUPPORT */
		INCPTR(2, p);
		GETSHORT(cishort, p);

#if PAP_SUPPORT

		if(cishort == PPP_PAP && cilen == CILEN_SHORT) {
#if EAP_SUPPORT

			/* If we were asking for EAP, then we need to stop that. */
			if(go->neg_eap)
				try_.neg_eap = 0;
			else
#endif /* EAP_SUPPORT */

#if CHAP_SUPPORT

				/* If we were asking for CHAP, then we need to stop that. */
				if(go->neg_chap)
					try_.neg_chap = 0;
				else
#endif /* CHAP_SUPPORT */

					/*
					 * If we weren't asking for CHAP or EAP, then we were asking for
					 * PAP, in which case this Nak is bad.
					 */
					goto bad;
		} else
#endif /* PAP_SUPPORT */

#if CHAP_SUPPORT
			if(cishort == PPP_CHAP && cilen == CILEN_CHAP) {
				GETCHAR(cichar, p);
#if EAP_SUPPORT

				/* Stop asking for EAP, if we were. */
				if(go->neg_eap) {
					try_.neg_eap = 0;

					/* Try to set up to use their suggestion, if possible */
					if(CHAP_CANDIGEST(go->chap_mdtype, cichar))
						try_.chap_mdtype = CHAP_MDTYPE_D(cichar);
				} else
#endif /* EAP_SUPPORT */
					if(go->neg_chap) {
						/*
						 * We were asking for our preferred algorithm, they must
						 * want something different.
						 */
						if(cichar != CHAP_DIGEST(go->chap_mdtype)) {
							if(CHAP_CANDIGEST(go->chap_mdtype, cichar)) {
								/* Use their suggestion if we support it ... */
								try_.chap_mdtype = CHAP_MDTYPE_D(cichar);
							} else {
								/* ... otherwise, try our next-preferred algorithm. */
								try_.chap_mdtype &= ~(CHAP_MDTYPE(try_.chap_mdtype));

								if(try_.chap_mdtype == MDTYPE_NONE)  /* out of algos */
									try_.neg_chap = 0;
							}
						} else {
							/*
							 * Whoops, they Nak'd our algorithm of choice
							 * but then suggested it back to us.
							 */
							goto bad;
						}
					} else {
						/*
						 * Stop asking for PAP if we were asking for it.
						 */
#if PAP_SUPPORT
						try_.neg_upap = 0;
#endif /* PAP_SUPPORT */
					}

			} else
#endif /* CHAP_SUPPORT */
			{

#if EAP_SUPPORT

				/*
				 * If we were asking for EAP, and they're Conf-Naking EAP,
				 * well, that's just strange.  Nobody should do that.
				 */
				if(cishort == PPP_EAP && cilen == CILEN_SHORT && go->neg_eap)
					ppp_dbglog("Unexpected Conf-Nak for EAP");

				/*
				 * We don't recognize what they're suggesting.
				 * Stop asking for what we were asking for.
				 */
				if(go->neg_eap)
					try_.neg_eap = 0;
				else
#endif /* EAP_SUPPORT */

#if CHAP_SUPPORT
					if(go->neg_chap)
						try_.neg_chap = 0;
					else
#endif /* CHAP_SUPPORT */

#if PAP_SUPPORT
						if(1)
							try_.neg_upap = 0;
						else
#endif /* PAP_SUPPORT */
						{}

				p += cilen - CILEN_SHORT;
			}
	}

#if LQR_SUPPORT
	/*
	 * If they can't cope with our link quality protocol, we'll have
	 * to stop asking for LQR.  We haven't got any other protocol.
	 * If they Nak the reporting period, take their value XXX ?
	 */
	NAKCILQR(CI_QUALITY, neg_lqr,

	         if(cishort != PPP_LQR)
	         try_.neg_lqr = 0;
	         else
		         try_.lqr_period = cilong;
		        );

#endif /* LQR_SUPPORT */

	/*
	 * Only implementing CBCP...not the rest of the callback options
	 */
	NAKCICHAR(CI_CALLBACK, neg_cbcp,
	          try_.neg_cbcp = 0;
	          (void)cichar; /* if CHAP support is not compiled, cichar is set but not used, which makes some compilers complaining */
	         );

	/*
	 * Check for a looped-back line.
	 */
	NAKCILONG(CI_MAGICNUMBER, neg_magicnumber,
	          try_.magicnumber = magic();
	          looped_back = 1;
	         );

	/*
	 * Peer shouldn't send Nak for protocol compression or
	 * address/control compression requests; they should send
	 * a Reject instead.  If they send a Nak, treat it as a Reject.
	 */
	NAKCIVOID(CI_PCOMPRESSION, neg_pcompression);
	NAKCIVOID(CI_ACCOMPRESSION, neg_accompression);

#ifdef HAVE_MULTILINK

	/*
	 * Nak for MRRU option - accept their value if it is smaller
	 * than the one we want.
	 */
	if(go->neg_mrru) {
		NAKCISHORT(CI_MRRU, neg_mrru,

		           if(treat_as_reject)
		           try_.neg_mrru = 0;
		           else if(cishort <= wo->mrru)
			           try_.mrru = cishort;
			          );
	}

#else /* HAVE_MULTILINK */
	LWIP_UNUSED_ARG(treat_as_reject);
#endif /* HAVE_MULTILINK */

	/*
	 * Nak for short sequence numbers shouldn't be sent, treat it
	 * like a reject.
	 */
	NAKCIVOID(CI_SSNHF, neg_ssnhf);

	/*
	 * Nak of the endpoint discriminator option is not permitted,
	 * treat it like a reject.
	 */
	NAKCIENDP(CI_EPDISC, neg_endpoint);

	/*
	 * There may be remaining CIs, if the peer is requesting negotiation
	 * on an option that we didn't include in our request packet.
	 * If we see an option that we requested, or one we've already seen
	 * in this packet, then this packet is bad.
	 * If we wanted to respond by starting to negotiate on the requested
	 * option(s), we could, but we don't, because except for the
	 * authentication type and quality protocol, if we are not negotiating
	 * an option, it is because we were told not to.
	 * For the authentication type, the Nak from the peer means
	 * `let me authenticate myself with you' which is a bit pointless.
	 * For the quality protocol, the Nak means `ask me to send you quality
	 * reports', but if we didn't ask for them, we don't want them.
	 * An option we don't recognize represents the peer asking to
	 * negotiate some option we don't support, so ignore it.
	 */
	while(len >= CILEN_VOID) {
		GETCHAR(citype, p);
		GETCHAR(cilen, p);

		if(cilen < CILEN_VOID || (len -= cilen) < 0)
			goto bad;

		next = p + cilen - 2;

		switch(citype) {
			case CI_MRU:
				if((go->neg_mru && go->mru != PPP_DEFMRU)
				        || no.neg_mru || cilen != CILEN_SHORT)
					goto bad;

				GETSHORT(cishort, p);

				if(cishort < PPP_DEFMRU) {
					try_.neg_mru = 1;
					try_.mru = cishort;
				}

				break;

			case CI_ASYNCMAP:
				if((go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF)
				        || no.neg_asyncmap || cilen != CILEN_LONG)
					goto bad;

				break;

			case CI_AUTHTYPE:
				if(0
#if CHAP_SUPPORT
				        || go->neg_chap || no.neg_chap
#endif /* CHAP_SUPPORT */
#if PAP_SUPPORT
				        || go->neg_upap || no.neg_upap
#endif /* PAP_SUPPORT */
#if EAP_SUPPORT
				        || go->neg_eap || no.neg_eap
#endif /* EAP_SUPPORT */
				  )
					goto bad;

				break;

			case CI_MAGICNUMBER:
				if(go->neg_magicnumber || no.neg_magicnumber ||
				        cilen != CILEN_LONG)
					goto bad;

				break;

			case CI_PCOMPRESSION:
				if(go->neg_pcompression || no.neg_pcompression
				        || cilen != CILEN_VOID)
					goto bad;

				break;

			case CI_ACCOMPRESSION:
				if(go->neg_accompression || no.neg_accompression
				        || cilen != CILEN_VOID)
					goto bad;

				break;
#if LQR_SUPPORT

			case CI_QUALITY:
				if(go->neg_lqr || no.neg_lqr || cilen != CILEN_LQR)
					goto bad;

				break;
#endif /* LQR_SUPPORT */
#ifdef HAVE_MULTILINK

			case CI_MRRU:
				if(go->neg_mrru || no.neg_mrru || cilen != CILEN_SHORT)
					goto bad;

				break;
#endif /* HAVE_MULTILINK */

			case CI_SSNHF:
				if(go->neg_ssnhf || no.neg_ssnhf || cilen != CILEN_VOID)
					goto bad;

				try_.neg_ssnhf = 1;
				break;

			case CI_EPDISC:
				if(go->neg_endpoint || no.neg_endpoint || cilen < CILEN_CHAR)
					goto bad;

				break;

			default:
				break;
		}

		p = next;
	}

	/*
	 * OK, the Nak is good.  Now we can update state.
	 * If there are any options left we ignore them.
	 */
	if(f->state != PPP_FSM_OPENED) {
		if(looped_back) {
			if(++try_.numloops >= pcb->settings.lcp_loopbackfail) {
				ppp_notice("Serial line is looped back.");
				pcb->err_code = PPPERR_LOOPBACK;
				lcp_close(f->pcb, "Loopback detected");
			}
		} else
			try_.numloops = 0;

		*go = try_;
	}

	return 1;

bad:
	LCPDEBUG(("lcp_nakci: received bad Nak!"));
	return 0;
}


/*
 * lcp_rejci - Peer has Rejected some of our CIs.
 * This should not modify any state if the Reject is bad
 * or if LCP is in the OPENED state.
 *
 * Returns:
 *	0 - Reject was bad.
 *	1 - Reject was good.
 */
static int lcp_rejci(fsm* f, u_char* p, int len)
{
	ppp_pcb* pcb = f->pcb;
	lcp_options* go = &pcb->lcp_gotoptions;
	u_char cichar;
	u_short cishort;
	u32_t cilong;
	lcp_options try_;		/* options to request next time */

	try_ = *go;

	/*
	 * Any Rejected CIs must be in exactly the same order that we sent.
	 * Check packet length and CI length at each step.
	 * If we find any deviations, then this packet is bad.
	 */
#define REJCIVOID(opt, neg) \
    if (go->neg && \
	len >= CILEN_VOID && \
	p[1] == CILEN_VOID && \
	p[0] == opt) { \
	len -= CILEN_VOID; \
	INCPTR(CILEN_VOID, p); \
	try_.neg = 0; \
    }
#define REJCISHORT(opt, neg, val) \
    if (go->neg && \
	len >= CILEN_SHORT && \
	p[1] == CILEN_SHORT && \
	p[0] == opt) { \
	len -= CILEN_SHORT; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	/* Check rejected value. */ \
	if (cishort != val) \
	    goto bad; \
	try_.neg = 0; \
    }

#if CHAP_SUPPORT && EAP_SUPPORT && PAP_SUPPORT
#define REJCICHAP(opt, neg, val) \
    if (go->neg && \
	len >= CILEN_CHAP && \
	p[1] == CILEN_CHAP && \
	p[0] == opt) { \
	len -= CILEN_CHAP; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	GETCHAR(cichar, p); \
	/* Check rejected value. */ \
	if ((cishort != PPP_CHAP) || (cichar != (CHAP_DIGEST(val)))) \
	    goto bad; \
	try_.neg = 0; \
	try_.neg_eap = try_.neg_upap = 0; \
    }
#endif /* CHAP_SUPPORT && EAP_SUPPORT && PAP_SUPPORT */

#if CHAP_SUPPORT && !EAP_SUPPORT && PAP_SUPPORT
#define REJCICHAP(opt, neg, val) \
    if (go->neg && \
	len >= CILEN_CHAP && \
	p[1] == CILEN_CHAP && \
	p[0] == opt) { \
	len -= CILEN_CHAP; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	GETCHAR(cichar, p); \
	/* Check rejected value. */ \
	if ((cishort != PPP_CHAP) || (cichar != (CHAP_DIGEST(val)))) \
	    goto bad; \
	try_.neg = 0; \
	try_.neg_upap = 0; \
    }
#endif /* CHAP_SUPPORT && !EAP_SUPPORT && PAP_SUPPORT */

#if CHAP_SUPPORT && EAP_SUPPORT && !PAP_SUPPORT
#define REJCICHAP(opt, neg, val) \
    if (go->neg && \
	len >= CILEN_CHAP && \
	p[1] == CILEN_CHAP && \
	p[0] == opt) { \
	len -= CILEN_CHAP; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	GETCHAR(cichar, p); \
	/* Check rejected value. */ \
	if ((cishort != PPP_CHAP) || (cichar != (CHAP_DIGEST(val)))) \
	    goto bad; \
	try_.neg = 0; \
	try_.neg_eap = 0; \
    }
#endif /* CHAP_SUPPORT && EAP_SUPPORT && !PAP_SUPPORT */

#if CHAP_SUPPORT && !EAP_SUPPORT && !PAP_SUPPORT
#define REJCICHAP(opt, neg, val) \
    if (go->neg && \
	len >= CILEN_CHAP && \
	p[1] == CILEN_CHAP && \
	p[0] == opt) { \
	len -= CILEN_CHAP; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	GETCHAR(cichar, p); \
	/* Check rejected value. */ \
	if ((cishort != PPP_CHAP) || (cichar != (CHAP_DIGEST(val)))) \
	    goto bad; \
	try_.neg = 0; \
    }
#endif /* CHAP_SUPPORT && !EAP_SUPPORT && !PAP_SUPPORT */

#define REJCILONG(opt, neg, val) \
    if (go->neg && \
	len >= CILEN_LONG && \
	p[1] == CILEN_LONG && \
	p[0] == opt) { \
	len -= CILEN_LONG; \
	INCPTR(2, p); \
	GETLONG(cilong, p); \
	/* Check rejected value. */ \
	if (cilong != val) \
	    goto bad; \
	try_.neg = 0; \
    }
#if LQR_SUPPORT
#define REJCILQR(opt, neg, val) \
    if (go->neg && \
	len >= CILEN_LQR && \
	p[1] == CILEN_LQR && \
	p[0] == opt) { \
	len -= CILEN_LQR; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	GETLONG(cilong, p); \
	/* Check rejected value. */ \
	if (cishort != PPP_LQR || cilong != val) \
	    goto bad; \
	try_.neg = 0; \
    }
#endif /* LQR_SUPPORT */
#define REJCICBCP(opt, neg, val) \
    if (go->neg && \
	len >= CILEN_CBCP && \
	p[1] == CILEN_CBCP && \
	p[0] == opt) { \
	len -= CILEN_CBCP; \
	INCPTR(2, p); \
	GETCHAR(cichar, p); \
	/* Check rejected value. */ \
	if (cichar != val) \
	    goto bad; \
	try_.neg = 0; \
    }
#define REJCIENDP(opt, neg, class, val, vlen) \
    if (go->neg && \
	len >= CILEN_CHAR + vlen && \
	p[0] == opt && \
	p[1] == CILEN_CHAR + vlen) { \
	int i; \
	len -= CILEN_CHAR + vlen; \
	INCPTR(2, p); \
	GETCHAR(cichar, p); \
	if (cichar != class) \
	    goto bad; \
	for (i = 0; i < vlen; ++i) { \
	    GETCHAR(cichar, p); \
	    if (cichar != val[i]) \
		goto bad; \
	} \
	try_.neg = 0; \
    }

	REJCISHORT(CI_MRU, neg_mru, go->mru);
	REJCILONG(CI_ASYNCMAP, neg_asyncmap, go->asyncmap);
#if EAP_SUPPORT
	REJCISHORT(CI_AUTHTYPE, neg_eap, PPP_EAP);

	if(!go->neg_eap) {
#endif /* EAP_SUPPORT */
#if CHAP_SUPPORT
		REJCICHAP(CI_AUTHTYPE, neg_chap, go->chap_mdtype);

		if(!go->neg_chap) {
#endif /* CHAP_SUPPORT */
#if PAP_SUPPORT
			REJCISHORT(CI_AUTHTYPE, neg_upap, PPP_PAP);
#endif /* PAP_SUPPORT */
#if CHAP_SUPPORT
		}

#endif /* CHAP_SUPPORT */
#if EAP_SUPPORT
	}

#endif /* EAP_SUPPORT */
#if LQR_SUPPORT
	REJCILQR(CI_QUALITY, neg_lqr, go->lqr_period);
#endif /* LQR_SUPPORT */
	REJCICBCP(CI_CALLBACK, neg_cbcp, CBCP_OPT);
	REJCILONG(CI_MAGICNUMBER, neg_magicnumber, go->magicnumber);
	REJCIVOID(CI_PCOMPRESSION, neg_pcompression);
	REJCIVOID(CI_ACCOMPRESSION, neg_accompression);
#ifdef HAVE_MULTILINK
	REJCISHORT(CI_MRRU, neg_mrru, go->mrru);
#endif /* HAVE_MULTILINK */
	REJCIVOID(CI_SSNHF, neg_ssnhf);
	REJCIENDP(CI_EPDISC, neg_endpoint, go->endpoint.class_,
	          go->endpoint.value, go->endpoint.length);

	/*
	 * If there are any remaining CIs, then this packet is bad.
	 */
	if(len != 0)
		goto bad;

	/*
	 * Now we can update state.
	 */
	if(f->state != PPP_FSM_OPENED)
		*go = try_;

	return 1;

bad:
	LCPDEBUG(("lcp_rejci: received bad Reject!"));
	return 0;
}


/*
 * lcp_reqci - Check the peer's requested CIs and send appropriate response.
 *
 * Returns: CONFACK, CONFNAK or CONFREJ and input packet modified
 * appropriately.  If reject_if_disagree is non-zero, doesn't return
 * CONFNAK; returns CONFREJ if it can't return CONFACK.
 *
 * inp = Requested CIs
 * lenp = Length of requested CIs
 */
static int lcp_reqci(fsm* f, u_char* inp, int* lenp, int reject_if_disagree)
{
	ppp_pcb* pcb = f->pcb;
	lcp_options* go = &pcb->lcp_gotoptions;
	lcp_options* ho = &pcb->lcp_hisoptions;
	lcp_options* ao = &pcb->lcp_allowoptions;
	u_char* cip, *next;		/* Pointer to current and next CIs */
	int cilen, citype, cichar;	/* Parsed len, type, char value */
	u_short cishort;		/* Parsed short value */
	u32_t cilong;		/* Parse long value */
	int rc = CONFACK;		/* Final packet return code */
	int orc;			/* Individual option return code */
	u_char* p;			/* Pointer to next char to parse */
	u_char* rejp;		/* Pointer to next char in reject frame */
	struct pbuf* nakp;          /* Nak buffer */
	u_char* nakoutp;		/* Pointer to next char in Nak frame */
	int l = *lenp;		/* Length left */

	/*
	 * Reset all his options.
	 */
	BZERO(ho, sizeof(*ho));

	/*
	 * Process all his options.
	 */
	next = inp;
	nakp = pbuf_alloc(PBUF_RAW, (u16_t)(PPP_CTRL_PBUF_MAX_SIZE), PPP_CTRL_PBUF_TYPE);

	if(NULL == nakp)
		return 0;

	if(nakp->tot_len != nakp->len) {
		pbuf_free(nakp);
		return 0;
	}

	nakoutp = (u_char*)nakp->payload;
	rejp = inp;

	while(l) {
		orc = CONFACK;			/* Assume success */
		cip = p = next;			/* Remember begining of CI */

		if(l < 2 ||			/* Not enough data for CI header or */
		        p[1] < 2 ||			/*  CI length too small or */
		        p[1] > l) {			/*  CI length too big? */
			LCPDEBUG(("lcp_reqci: bad CI length!"));
			orc = CONFREJ;		/* Reject bad CI */
			cilen = l;			/* Reject till end of packet */
			l = 0;			/* Don't loop again */
			citype = 0;
			goto endswitch;
		}

		GETCHAR(citype, p);		/* Parse CI type */
		GETCHAR(cilen, p);		/* Parse CI length */
		l -= cilen;			/* Adjust remaining length */
		next += cilen;			/* Step to next CI */

		switch(citype) {		/* Check CI type */
			case CI_MRU:
				if(!ao->neg_mru ||		/* Allow option? */
				        cilen != CILEN_SHORT) {	/* Check CI length */
					orc = CONFREJ;		/* Reject CI */
					break;
				}

				GETSHORT(cishort, p);	/* Parse MRU */

				/*
				 * He must be able to receive at least our minimum.
				 * No need to check a maximum.  If he sends a large number,
				 * we'll just ignore it.
				 */
				if(cishort < PPP_MINMRU) {
					orc = CONFNAK;		/* Nak CI */
					PUTCHAR(CI_MRU, nakoutp);
					PUTCHAR(CILEN_SHORT, nakoutp);
					PUTSHORT(PPP_MINMRU, nakoutp);	/* Give him a hint */
					break;
				}

				ho->neg_mru = 1;		/* Remember he sent MRU */
				ho->mru = cishort;		/* And remember value */
				break;

			case CI_ASYNCMAP:
				if(!ao->neg_asyncmap ||
				        cilen != CILEN_LONG) {
					orc = CONFREJ;
					break;
				}

				GETLONG(cilong, p);

				/*
				 * Asyncmap must have set at least the bits
				 * which are set in lcp_allowoptions[unit].asyncmap.
				 */
				if((ao->asyncmap & ~cilong) != 0) {
					orc = CONFNAK;
					PUTCHAR(CI_ASYNCMAP, nakoutp);
					PUTCHAR(CILEN_LONG, nakoutp);
					PUTLONG(ao->asyncmap | cilong, nakoutp);
					break;
				}

				ho->neg_asyncmap = 1;
				ho->asyncmap = cilong;
				break;

			case CI_AUTHTYPE:
				if(cilen < CILEN_SHORT ||
				        !(0
#if PAP_SUPPORT
				          || ao->neg_upap
#endif /* PAP_SUPPORT */
#if CHAP_SUPPORT
				          || ao->neg_chap
#endif /* CHAP_SUPPORT */
#if EAP_SUPPORT
				          || ao->neg_eap
#endif /* EAP_SUPPORT */
				         )) {
					/*
					 * Reject the option if we're not willing to authenticate.
					 */
					ppp_dbglog("No auth is possible");
					orc = CONFREJ;
					break;
				}

				GETSHORT(cishort, p);

				/*
				 * Authtype must be PAP, CHAP, or EAP.
				 *
				 * Note: if more than one of ao->neg_upap, ao->neg_chap, and
				 * ao->neg_eap are set, and the peer sends a Configure-Request
				 * with two or more authenticate-protocol requests, then we will
				 * reject the second request.
				 * Whether we end up doing CHAP, UPAP, or EAP depends then on
				 * the ordering of the CIs in the peer's Configure-Request.
				     */

#if PAP_SUPPORT

				if(cishort == PPP_PAP) {
					/* we've already accepted CHAP or EAP */
					if(0
#if CHAP_SUPPORT
					        || ho->neg_chap
#endif /* CHAP_SUPPORT */
#if EAP_SUPPORT
					        || ho->neg_eap
#endif /* EAP_SUPPORT */
					        || cilen != CILEN_SHORT) {
						LCPDEBUG(("lcp_reqci: rcvd AUTHTYPE PAP, rejecting..."));
						orc = CONFREJ;
						break;
					}

					if(!ao->neg_upap) {	/* we don't want to do PAP */
						orc = CONFNAK;	/* NAK it and suggest CHAP or EAP */
						PUTCHAR(CI_AUTHTYPE, nakoutp);
#if EAP_SUPPORT

						if(ao->neg_eap) {
							PUTCHAR(CILEN_SHORT, nakoutp);
							PUTSHORT(PPP_EAP, nakoutp);
						} else {
#endif /* EAP_SUPPORT */
#if CHAP_SUPPORT
							PUTCHAR(CILEN_CHAP, nakoutp);
							PUTSHORT(PPP_CHAP, nakoutp);
							PUTCHAR(CHAP_DIGEST(ao->chap_mdtype), nakoutp);
#endif /* CHAP_SUPPORT */
#if EAP_SUPPORT
						}

#endif /* EAP_SUPPORT */
						break;
					}

					ho->neg_upap = 1;
					break;
				}

#endif /* PAP_SUPPORT */
#if CHAP_SUPPORT

				if(cishort == PPP_CHAP) {
					/* we've already accepted PAP or EAP */
					if(
#if PAP_SUPPORT
					    ho->neg_upap ||
#endif /* PAP_SUPPORT */
#if EAP_SUPPORT
					    ho->neg_eap ||
#endif /* EAP_SUPPORT */
					    cilen != CILEN_CHAP) {
						LCPDEBUG(("lcp_reqci: rcvd AUTHTYPE CHAP, rejecting..."));
						orc = CONFREJ;
						break;
					}

					if(!ao->neg_chap) {	/* we don't want to do CHAP */
						orc = CONFNAK;	/* NAK it and suggest EAP or PAP */
						PUTCHAR(CI_AUTHTYPE, nakoutp);
						PUTCHAR(CILEN_SHORT, nakoutp);
#if EAP_SUPPORT

						if(ao->neg_eap) {
							PUTSHORT(PPP_EAP, nakoutp);
						} else
#endif /* EAP_SUPPORT */
#if PAP_SUPPORT
							if(1) {
								PUTSHORT(PPP_PAP, nakoutp);
							} else
#endif /* PAP_SUPPORT */
							{}

						break;
					}

					GETCHAR(cichar, p);	/* get digest type */

					if(!(CHAP_CANDIGEST(ao->chap_mdtype, cichar))) {
						/*
						 * We can't/won't do the requested type,
						 * suggest something else.
						 */
						orc = CONFNAK;
						PUTCHAR(CI_AUTHTYPE, nakoutp);
						PUTCHAR(CILEN_CHAP, nakoutp);
						PUTSHORT(PPP_CHAP, nakoutp);
						PUTCHAR(CHAP_DIGEST(ao->chap_mdtype), nakoutp);
						break;
					}

					ho->chap_mdtype = CHAP_MDTYPE_D(cichar); /* save md type */
					ho->neg_chap = 1;
					break;
				}

#endif /* CHAP_SUPPORT */
#if EAP_SUPPORT

				if(cishort == PPP_EAP) {
					/* we've already accepted CHAP or PAP */
					if(
#if CHAP_SUPPORT
					    ho->neg_chap ||
#endif /* CHAP_SUPPORT */
#if PAP_SUPPORT
					    ho->neg_upap ||
#endif /* PAP_SUPPORT */
					    cilen != CILEN_SHORT) {
						LCPDEBUG(("lcp_reqci: rcvd AUTHTYPE EAP, rejecting..."));
						orc = CONFREJ;
						break;
					}

					if(!ao->neg_eap) {	/* we don't want to do EAP */
						orc = CONFNAK;	/* NAK it and suggest CHAP or PAP */
						PUTCHAR(CI_AUTHTYPE, nakoutp);
#if CHAP_SUPPORT

						if(ao->neg_chap) {
							PUTCHAR(CILEN_CHAP, nakoutp);
							PUTSHORT(PPP_CHAP, nakoutp);
							PUTCHAR(CHAP_DIGEST(ao->chap_mdtype), nakoutp);
						} else
#endif /* CHAP_SUPPORT */
#if PAP_SUPPORT
							if(1) {
								PUTCHAR(CILEN_SHORT, nakoutp);
								PUTSHORT(PPP_PAP, nakoutp);
							} else
#endif /* PAP_SUPPORT */
							{}

						break;
					}

					ho->neg_eap = 1;
					break;
				}

#endif /* EAP_SUPPORT */

				/*
				 * We don't recognize the protocol they're asking for.
				 * Nak it with something we're willing to do.
				 * (At this point we know ao->neg_upap || ao->neg_chap ||
				 * ao->neg_eap.)
				 */
				orc = CONFNAK;
				PUTCHAR(CI_AUTHTYPE, nakoutp);

#if EAP_SUPPORT

				if(ao->neg_eap) {
					PUTCHAR(CILEN_SHORT, nakoutp);
					PUTSHORT(PPP_EAP, nakoutp);
				} else
#endif /* EAP_SUPPORT */
#if CHAP_SUPPORT
					if(ao->neg_chap) {
						PUTCHAR(CILEN_CHAP, nakoutp);
						PUTSHORT(PPP_CHAP, nakoutp);
						PUTCHAR(CHAP_DIGEST(ao->chap_mdtype), nakoutp);
					} else
#endif /* CHAP_SUPPORT */
#if PAP_SUPPORT
						if(1) {
							PUTCHAR(CILEN_SHORT, nakoutp);
							PUTSHORT(PPP_PAP, nakoutp);
						} else
#endif /* PAP_SUPPORT */
						{}

				break;

#if LQR_SUPPORT

			case CI_QUALITY:
				if(!ao->neg_lqr ||
				        cilen != CILEN_LQR) {
					orc = CONFREJ;
					break;
				}

				GETSHORT(cishort, p);
				GETLONG(cilong, p);

				/*
				 * Check the protocol and the reporting period.
				 * XXX When should we Nak this, and what with?
				 */
				if(cishort != PPP_LQR) {
					orc = CONFNAK;
					PUTCHAR(CI_QUALITY, nakoutp);
					PUTCHAR(CILEN_LQR, nakoutp);
					PUTSHORT(PPP_LQR, nakoutp);
					PUTLONG(ao->lqr_period, nakoutp);
					break;
				}

				break;
#endif /* LQR_SUPPORT */

			case CI_MAGICNUMBER:
				if(!(ao->neg_magicnumber || go->neg_magicnumber) ||
				        cilen != CILEN_LONG) {
					orc = CONFREJ;
					break;
				}

				GETLONG(cilong, p);

				/*
				 * He must have a different magic number.
				 */
				if(go->neg_magicnumber &&
				        cilong == go->magicnumber) {
					cilong = magic();	/* Don't put magic() inside macro! */
					orc = CONFNAK;
					PUTCHAR(CI_MAGICNUMBER, nakoutp);
					PUTCHAR(CILEN_LONG, nakoutp);
					PUTLONG(cilong, nakoutp);
					break;
				}

				ho->neg_magicnumber = 1;
				ho->magicnumber = cilong;
				break;


			case CI_PCOMPRESSION:
				if(!ao->neg_pcompression ||
				        cilen != CILEN_VOID) {
					orc = CONFREJ;
					break;
				}

				ho->neg_pcompression = 1;
				break;

			case CI_ACCOMPRESSION:
				if(!ao->neg_accompression ||
				        cilen != CILEN_VOID) {
					orc = CONFREJ;
					break;
				}

				ho->neg_accompression = 1;
				break;

#ifdef HAVE_MULTILINK

			case CI_MRRU:
				if(!ao->neg_mrru
				        || !multilink
				        || cilen != CILEN_SHORT) {
					orc = CONFREJ;
					break;
				}

				GETSHORT(cishort, p);
				/* possibly should insist on a minimum/maximum MRRU here */
				ho->neg_mrru = 1;
				ho->mrru = cishort;
				break;
#endif /* HAVE_MULTILINK */

			case CI_SSNHF:
				if(!ao->neg_ssnhf
#ifdef HAVE_MULTILINK
				        || !multilink
#endif /* HAVE_MULTILINK */
				        || cilen != CILEN_VOID) {
					orc = CONFREJ;
					break;
				}

				ho->neg_ssnhf = 1;
				break;

			case CI_EPDISC:
				if(!ao->neg_endpoint ||
				        cilen < CILEN_CHAR ||
				        cilen > CILEN_CHAR + MAX_ENDP_LEN) {
					orc = CONFREJ;
					break;
				}

				GETCHAR(cichar, p);
				cilen -= CILEN_CHAR;
				ho->neg_endpoint = 1;
				ho->endpoint.class_ = cichar;
				ho->endpoint.length = cilen;
				MEMCPY(ho->endpoint.value, p, cilen);
				INCPTR(cilen, p);
				break;

			default:
				LCPDEBUG(("lcp_reqci: rcvd unknown option %d", citype));
				orc = CONFREJ;
				break;
		}

endswitch:

		if(orc == CONFACK &&		/* Good CI */
		        rc != CONFACK)		/*  but prior CI wasnt? */
			continue;			/* Don't send this one */

		if(orc == CONFNAK) {		/* Nak this CI? */
			if(reject_if_disagree	/* Getting fed up with sending NAKs? */
			        && citype != CI_MAGICNUMBER) {
				orc = CONFREJ;		/* Get tough if so */
			} else {
				if(rc == CONFREJ)	/* Rejecting prior CI? */
					continue;		/* Don't send this one */

				rc = CONFNAK;
			}
		}

		if(orc == CONFREJ) {		/* Reject this CI */
			rc = CONFREJ;

			if(cip != rejp)		/* Need to move rejected CI? */
				MEMCPY(rejp, cip, cilen); /* Move it */

			INCPTR(cilen, rejp);	/* Update output pointer */
		}
	}

	/*
	 * If we wanted to send additional NAKs (for unsent CIs), the
	 * code would go here.  The extra NAKs would go at *nakoutp.
	 * At present there are no cases where we want to ask the
	 * peer to negotiate an option.
	 */

	switch(rc) {
		case CONFACK:
			*lenp = next - inp;
			break;

		case CONFNAK:
			/*
			 * Copy the Nak'd options from the nak buffer to the caller's buffer.
			 */
			*lenp = nakoutp - (u_char*)nakp->payload;
			MEMCPY(inp, nakp->payload, *lenp);
			break;

		case CONFREJ:
			*lenp = rejp - inp;
			break;

		default:
			break;
	}

	pbuf_free(nakp);
	LCPDEBUG(("lcp_reqci: returning CONF%s.", CODENAME(rc)));
	return (rc);			/* Return final code */
}


/*
 * lcp_up - LCP has come UP.
 */
static void lcp_up(fsm* f)
{
	ppp_pcb* pcb = f->pcb;
	lcp_options* wo = &pcb->lcp_wantoptions;
	lcp_options* ho = &pcb->lcp_hisoptions;
	lcp_options* go = &pcb->lcp_gotoptions;
	lcp_options* ao = &pcb->lcp_allowoptions;
	int mtu, mru;

	if(!go->neg_magicnumber)
		go->magicnumber = 0;

	if(!ho->neg_magicnumber)
		ho->magicnumber = 0;

	/*
	 * Set our MTU to the smaller of the MTU we wanted and
	 * the MRU our peer wanted.  If we negotiated an MRU,
	 * set our MRU to the larger of value we wanted and
	 * the value we got in the negotiation.
	 * Note on the MTU: the link MTU can be the MRU the peer wanted,
	 * the interface MTU is set to the lowest of that, the
	 * MTU we want to use, and our link MRU.
	 */
	mtu = ho->neg_mru ? ho->mru : PPP_MRU;
	mru = go->neg_mru ? LWIP_MAX(wo->mru, go->mru) : PPP_MRU;
#ifdef HAVE_MULTILINK

	if(!(multilink && go->neg_mrru && ho->neg_mrru))
#endif /* HAVE_MULTILINK */
		netif_set_mtu(pcb, LWIP_MIN(LWIP_MIN(mtu, mru), ao->mru));

	ppp_send_config(pcb, mtu,
	                (ho->neg_asyncmap ? ho->asyncmap : 0xffffffff),
	                ho->neg_pcompression, ho->neg_accompression);
	ppp_recv_config(pcb, mru,
	                (pcb->settings.lax_recv ? 0 : go->neg_asyncmap ? go->asyncmap : 0xffffffff),
	                go->neg_pcompression, go->neg_accompression);

	if(ho->neg_mru)
		pcb->peer_mru = ho->mru;

	lcp_echo_lowerup(f->pcb);  /* Enable echo messages */

	link_established(pcb);
}


/*
 * lcp_down - LCP has gone DOWN.
 *
 * Alert other protocols.
 */
static void lcp_down(fsm* f)
{
	ppp_pcb* pcb = f->pcb;
	lcp_options* go = &pcb->lcp_gotoptions;

	lcp_echo_lowerdown(f->pcb);

	link_down(pcb);

	ppp_send_config(pcb, PPP_MRU, 0xffffffff, 0, 0);
	ppp_recv_config(pcb, PPP_MRU,
	                (go->neg_asyncmap ? go->asyncmap : 0xffffffff),
	                go->neg_pcompression, go->neg_accompression);
	pcb->peer_mru = PPP_MRU;
}


/*
 * lcp_starting - LCP needs the lower layer up.
 */
static void lcp_starting(fsm* f)
{
	ppp_pcb* pcb = f->pcb;
	link_required(pcb);
}


/*
 * lcp_finished - LCP has finished with the lower layer.
 */
static void lcp_finished(fsm* f)
{
	ppp_pcb* pcb = f->pcb;
	link_terminated(pcb);
}


#if PRINTPKT_SUPPORT
/*
 * lcp_printpkt - print the contents of an LCP packet.
 */
static const char* const lcp_codenames[] = {
	"ConfReq", "ConfAck", "ConfNak", "ConfRej",
	"TermReq", "TermAck", "CodeRej", "ProtRej",
	"EchoReq", "EchoRep", "DiscReq", "Ident",
	"TimeRem"
};

static int lcp_printpkt(const u_char* p, int plen,
                        void (*printer)(void*, const char*, ...), void* arg)
{
	int code, id, len, olen, i;
	const u_char* pstart, *optend;
	u_short cishort;
	u32_t cilong;

	if(plen < HEADERLEN)
		return 0;

	pstart = p;
	GETCHAR(code, p);
	GETCHAR(id, p);
	GETSHORT(len, p);

	if(len < HEADERLEN || len > plen)
		return 0;

	if(code >= 1 && code <= (int)LWIP_ARRAYSIZE(lcp_codenames))
		printer(arg, " %s", lcp_codenames[code - 1]);
	else
		printer(arg, " code=0x%x", code);

	printer(arg, " id=0x%x", id);
	len -= HEADERLEN;

	switch(code) {
		case CONFREQ:
		case CONFACK:
		case CONFNAK:
		case CONFREJ:

			/* print option list */
			while(len >= 2) {
				GETCHAR(code, p);
				GETCHAR(olen, p);
				p -= 2;

				if(olen < 2 || olen > len) {
					break;
				}

				printer(arg, " <");
				len -= olen;
				optend = p + olen;

				switch(code) {
					case CI_MRU:
						if(olen == CILEN_SHORT) {
							p += 2;
							GETSHORT(cishort, p);
							printer(arg, "mru %d", cishort);
						}

						break;

					case CI_ASYNCMAP:
						if(olen == CILEN_LONG) {
							p += 2;
							GETLONG(cilong, p);
							printer(arg, "asyncmap 0x%x", cilong);
						}

						break;

					case CI_AUTHTYPE:
						if(olen >= CILEN_SHORT) {
							p += 2;
							printer(arg, "auth ");
							GETSHORT(cishort, p);

							switch(cishort) {
#if PAP_SUPPORT

								case PPP_PAP:
									printer(arg, "pap");
									break;
#endif /* PAP_SUPPORT */
#if CHAP_SUPPORT

								case PPP_CHAP:
									printer(arg, "chap");

									if(p < optend) {
										switch(*p) {
											case CHAP_MD5:
												printer(arg, " MD5");
												++p;
												break;
#if MSCHAP_SUPPORT

											case CHAP_MICROSOFT:
												printer(arg, " MS");
												++p;
												break;

											case CHAP_MICROSOFT_V2:
												printer(arg, " MS-v2");
												++p;
												break;
#endif /* MSCHAP_SUPPORT */

											default:
												break;
										}
									}

									break;
#endif /* CHAP_SUPPORT */
#if EAP_SUPPORT

								case PPP_EAP:
									printer(arg, "eap");
									break;
#endif /* EAP_SUPPORT */

								default:
									printer(arg, "0x%x", cishort);
							}
						}

						break;
#if LQR_SUPPORT

					case CI_QUALITY:
						if(olen >= CILEN_SHORT) {
							p += 2;
							printer(arg, "quality ");
							GETSHORT(cishort, p);

							switch(cishort) {
								case PPP_LQR:
									printer(arg, "lqr");
									break;

								default:
									printer(arg, "0x%x", cishort);
							}
						}

						break;
#endif /* LQR_SUPPORT */

					case CI_CALLBACK:
						if(olen >= CILEN_CHAR) {
							p += 2;
							printer(arg, "callback ");
							GETCHAR(cishort, p);

							switch(cishort) {
								case CBCP_OPT:
									printer(arg, "CBCP");
									break;

								default:
									printer(arg, "0x%x", cishort);
							}
						}

						break;

					case CI_MAGICNUMBER:
						if(olen == CILEN_LONG) {
							p += 2;
							GETLONG(cilong, p);
							printer(arg, "magic 0x%x", cilong);
						}

						break;

					case CI_PCOMPRESSION:
						if(olen == CILEN_VOID) {
							p += 2;
							printer(arg, "pcomp");
						}

						break;

					case CI_ACCOMPRESSION:
						if(olen == CILEN_VOID) {
							p += 2;
							printer(arg, "accomp");
						}

						break;

					case CI_MRRU:
						if(olen == CILEN_SHORT) {
							p += 2;
							GETSHORT(cishort, p);
							printer(arg, "mrru %d", cishort);
						}

						break;

					case CI_SSNHF:
						if(olen == CILEN_VOID) {
							p += 2;
							printer(arg, "ssnhf");
						}

						break;

					case CI_EPDISC:
#ifdef HAVE_MULTILINK
						if(olen >= CILEN_CHAR) {
							struct epdisc epd;
							p += 2;
							GETCHAR(epd.class, p);
							epd.length = olen - CILEN_CHAR;

							if(epd.length > MAX_ENDP_LEN)
								epd.length = MAX_ENDP_LEN;

							if(epd.length > 0) {
								MEMCPY(epd.value, p, epd.length);
								p += epd.length;
							}

							printer(arg, "endpoint [%s]", epdisc_to_str(&epd));
						}

#else
						printer(arg, "endpoint");
#endif
						break;

					default:
						break;
				}

				while(p < optend) {
					GETCHAR(code, p);
					printer(arg, " %.2x", code);
				}

				printer(arg, ">");
			}

			break;

		case TERMACK:
		case TERMREQ:
			if(len > 0 && *p >= ' ' && *p < 0x7f) {
				printer(arg, " ");
				ppp_print_string(p, len, printer, arg);
				p += len;
				len = 0;
			}

			break;

		case ECHOREQ:
		case ECHOREP:
		case DISCREQ:
			if(len >= 4) {
				GETLONG(cilong, p);
				printer(arg, " magic=0x%x", cilong);
				len -= 4;
			}

			break;

		case IDENTIF:
		case TIMEREM:
			if(len >= 4) {
				GETLONG(cilong, p);
				printer(arg, " magic=0x%x", cilong);
				len -= 4;
			}

			if(code == TIMEREM) {
				if(len < 4)
					break;

				GETLONG(cilong, p);
				printer(arg, " seconds=%u", cilong);
				len -= 4;
			}

			if(len > 0) {
				printer(arg, " ");
				ppp_print_string(p, len, printer, arg);
				p += len;
				len = 0;
			}

			break;

		default:
			break;
	}

	/* print the rest of the bytes in the packet */
	for(i = 0; i < len && i < 32; ++i) {
		GETCHAR(code, p);
		printer(arg, " %.2x", code);
	}

	if(i < len) {
		printer(arg, " ...");
		p += len - i;
	}

	return p - pstart;
}
#endif /* PRINTPKT_SUPPORT */

/*
 * Time to shut down the link because there is nothing out there.
 */

static void LcpLinkFailure(fsm* f)
{
	ppp_pcb* pcb = f->pcb;

	if(f->state == PPP_FSM_OPENED) {
		ppp_info("No response to %d echo-requests", pcb->lcp_echos_pending);
		ppp_notice("Serial link appears to be disconnected.");
		pcb->err_code = PPPERR_PEERDEAD;
		lcp_close(pcb, "Peer not responding");
	}
}

/*
 * Timer expired for the LCP echo requests from this process.
 */

static void LcpEchoCheck(fsm* f)
{
	ppp_pcb* pcb = f->pcb;

	LcpSendEchoRequest(f);

	if(f->state != PPP_FSM_OPENED)
		return;

	/*
	 * Start the timer for the next interval.
	 */
	if(pcb->lcp_echo_timer_running)
		ppp_warn("assertion lcp_echo_timer_running==0 failed");

	TIMEOUT(LcpEchoTimeout, f, pcb->settings.lcp_echo_interval);
	pcb->lcp_echo_timer_running = 1;
}

/*
 * LcpEchoTimeout - Timer expired on the LCP echo
 */

static void LcpEchoTimeout(void* arg)
{
	fsm* f = (fsm*)arg;
	ppp_pcb* pcb = f->pcb;

	if(pcb->lcp_echo_timer_running != 0) {
		pcb->lcp_echo_timer_running = 0;
		LcpEchoCheck((fsm*) arg);
	}
}

/*
 * LcpEchoReply - LCP has received a reply to the echo
 */

static void lcp_received_echo_reply(fsm* f, int id, u_char* inp, int len)
{
	ppp_pcb* pcb = f->pcb;
	lcp_options* go = &pcb->lcp_gotoptions;
	u32_t magic_val;
	LWIP_UNUSED_ARG(id);

	/* Check the magic number - don't count replies from ourselves. */
	if(len < 4) {
		ppp_dbglog("lcp: received short Echo-Reply, length %d", len);
		return;
	}

	GETLONG(magic_val, inp);

	if(go->neg_magicnumber
	        && magic_val == go->magicnumber) {
		ppp_warn("appear to have received our own echo-reply!");
		return;
	}

	/* Reset the number of outstanding echo frames */
	pcb->lcp_echos_pending = 0;
}

/*
 * LcpSendEchoRequest - Send an echo request frame to the peer
 */

static void LcpSendEchoRequest(fsm* f)
{
	ppp_pcb* pcb = f->pcb;
	lcp_options* go = &pcb->lcp_gotoptions;
	u32_t lcp_magic;
	u_char pkt[4], *pktp;

	/*
	 * Detect the failure of the peer at this point.
	 */
	if(pcb->settings.lcp_echo_fails != 0) {
		if(pcb->lcp_echos_pending >= pcb->settings.lcp_echo_fails) {
			LcpLinkFailure(f);
			pcb->lcp_echos_pending = 0;
		}
	}

#if PPP_LCP_ADAPTIVE

	/*
	 * If adaptive echos have been enabled, only send the echo request if
	 * no traffic was received since the last one.
	 */
	if(pcb->settings.lcp_echo_adaptive) {
		static unsigned int last_pkts_in = 0;

#if PPP_STATS_SUPPORT
		update_link_stats(f->unit);
		link_stats_valid = 0;
#endif /* PPP_STATS_SUPPORT */

		if(link_stats.pkts_in != last_pkts_in) {
			last_pkts_in = link_stats.pkts_in;
			return;
		}
	}

#endif

	/*
	 * Make and send the echo request frame.
	 */
	if(f->state == PPP_FSM_OPENED) {
		lcp_magic = go->magicnumber;
		pktp = pkt;
		PUTLONG(lcp_magic, pktp);
		fsm_sdata(f, ECHOREQ, pcb->lcp_echo_number++, pkt, pktp - pkt);
		++pcb->lcp_echos_pending;
	}
}

/*
 * lcp_echo_lowerup - Start the timer for the LCP frame
 */

static void lcp_echo_lowerup(ppp_pcb* pcb)
{
	fsm* f = &pcb->lcp_fsm;

	/* Clear the parameters for generating echo frames */
	pcb->lcp_echos_pending      = 0;
	pcb->lcp_echo_number        = 0;
	pcb->lcp_echo_timer_running = 0;

	/* If a timeout interval is specified then start the timer */
	if(pcb->settings.lcp_echo_interval != 0)
		LcpEchoCheck(f);
}

/*
 * lcp_echo_lowerdown - Stop the timer for the LCP frame
 */

static void lcp_echo_lowerdown(ppp_pcb* pcb)
{
	fsm* f = &pcb->lcp_fsm;

	if(pcb->lcp_echo_timer_running != 0) {
		UNTIMEOUT(LcpEchoTimeout, f);
		pcb->lcp_echo_timer_running = 0;
	}
}

#endif /* PPP_SUPPORT */
